Disk drives typically include at least one disk (such as a magnetic, magneto-optical, or optical disk), a spindle motor for rotating the disk, and a head stack assembly (“HSA”). The HSA may include at least one head mounted on a suspension for writing data to and reading data from the disk. The head is typically driven at high velocities across the disk by a voice coil motor (“VCM”) to provide access to different locations.
Suspension dynamics play an important role in the performance of a disk drive as the head is moved back and forth across the disk. When the suspension becomes excited at a resonant frequency, the time required to settle on a desired track can be dramatically increased, and disk drive performance impacted. Moreover, in some cases, excitation of the disk drive suspension may result in off-track write errors or even contact between the head and the disk. Among the resonances of the disk drive suspension, the torsion and sway modes are typically the most critical.
In order to improve suspension dynamics and servo bandwidth, many disk drive suspensions now incorporate a damper. However, the effectiveness of dampers on typical suspensions depends heavily on the strain energy of those areas to which the dampers are attached. That is, applying a damper to a relatively stiff disk drive suspension often yields only modest improvements in disk drive suspension dynamics.
There is therefore a need for a disk drive suspension with improved dynamics.